The present invention relates to an apparatus for screwing and unscrewing the bottoms of watch casings, comprising a stand bearing a rotatable spindle provided with a tool for tightening and untightening watch-case bottoms.
The apparatus of the above mentioned type are known per se. They are generally provided with means, in most of the cases screw means, permitting rapid adjustment in the height of the spindle. However, when the apparatus is in use, the spindle rotates freely in the stand, without effecting any axial movement. The result is that, during the screwing of a bottom of a watch casing, it is necessary, after a certain number of revolutions, to adjust the axial position of the spindle, by means of the rapid adjusting means, otherwise the bottom disengages itself from the tool so that it slips within the tool. Such improper tool engagement results, on the one hand, in failure of the watch-case bottom to be correctly tightened and, on the other hand, gives rise to the danger of damaging the outer surface of the bottom. During the unscrewing of the bottom, it is also necessary to adjust the axial position of the spindle, after a certain number of revolutions, otherwise the bottom moves axially up against the tool and binds against it.
The purpose of the present invention is to remove these drawbacks.